Computer-to-plate inkjet printing technology is a plate-making technology utilizing an inkjet printer to spray plate-making ink onto a surface of a metal substrate or a polymer substrate to form an oleophilic graphic region, while the unsprayed region is a hydrophilic non-graphic region, thereby realizing printing through the hydrophilic and oleophilic contrast between the graphic region and the non-graphic region. By adopting the computer-to-plate inkjet printing technology, the post treatments such as exposing and developing are avoided, and the obtained printing plate allowing for computer-to-plate inkjet printing is good in resolution and press run. At present, most of the ink for the computer-to-plate inkjet printing is eco-solvent ink, when being used, the eco-solvent ink is easy to block the nozzle of printer, and the toxic and harmful gases produced in curing will pollute the environment. Water-based ink is good in printing smoothness, no toxic gas is released when curing, and meanwhile, through adjusting the concentration and compositions of the water-based ink, good image resolution and higher press run will be realized.
At present, the water-based ink for inkjet printing is mainly applied in plain paper or the paper with diffusion-resistant coating, films and various fiber-based substrates. Computer-to-plate inkjet printing technology adopts metal substrate, requires that the diffusion of the water-based ink on metal substrates can be effectively controlled, and meanwhile, enables to ensure the hydrophilic and oleophilic contrast between the graphic area and the non-graphic area, thereby realizing good image resolution and press run when performing computer-to-plate inkjet printing.
Currently, among the quick-drying water-based inks used for inkjet printing, in the computer-to-plate inkjet printing technology launched by Israel VIM Company, the adopted ink is standard Epson water-based ink; however, such water-based ink is very expensive.